If you ever need to load two different files in production vs test, you can add some code to your main.ts file in your Angular project. The existing code includes the if statement and enableProdMode(), but you can easily add in the else to conditionally load a different file. In my case I don’t want google analytics posting to my production account.

import { environment } from './environments/environment';

//create a new element
const script = document.createElement('script');
if (environment.production) {
    enableProdMode();
    script.src = 'analytics.js';
} else {
    script.src = 'test-analytics.js';
}
//append that element into the dom
document.head.appendChild(script);